1. Field of the Invention
The present invention relates to surface protective coatings, and particularly, to metallic glassy alloy powders for antibacterial coating made from metallic, glassy Cu50Ti20Ni30 alloy nano-powders that are applied using a cold-spraying process.
2. Description of the Related Art
Surface protective coatings, which provide protection against corrosion and erosion and isolate the structural materials from chemical and physical interaction with the environment, is one of the vital applications of mechanically alloyed powders. Thermal spray and high velocity thermal spray coatings have been widely used in many vital applications, especially in the automotive aircraft industries. Unfortunately, thermal spray technology is not a proper process used for coating the desired bulk surfaces with metastable materials. This is attributed to the fact that thermal spray coating is not a solid-state process, since the coating materials are deposited on the surface of the substrate in a molten or semi-molten state to tailor the desired coat. Accordingly, it is expected that during the process, the feedstock metastable powders will suffer from crystallization and grain growth. Thus, all of the unique properties present in the original metastable powders would be absent after the coating process.
Most of the tools used in the medical and food sectors are made of austenitic stainless steel alloys (SUS316 and SUS304), which contain a high chromium content in the range between 12-20%. It is well established that using chromium metal as an alloying element in steel alloys greatly enhances the corrosion performance of such a traditional alloy. Although they have high corrosion resistance, SUS316 and SUS304 alloys do not possess antibacterial properties. Thus, infection and inflammation, which are usually promoted by adherence and colonization of bacteria onto the surfaces of stainless steel biomaterials, can be expected. Such a serious problem associated with bacterial adhesion may lead to significant complications resulting in a degradation of health, with many outcomes that may directly or indirectly affect human health.
The formation of biofilms in food products or food contact surfaces leads to severe problems with regards to hygienic standards and economic losses because of food spoilage. A new horizon related to the employing of nanoparticles as antimicrobials and antibacterial agents in the area of in the food industry has shown promising results on the capability of different types of fine powders (e.g., Ag, Au, Cu, CuO, MgO, Al2O3, TiO2, ZnO) to kill and resist agglomerations of many types of bacteria. A TiN coating also showed attractive results related to significant reduction of bacterial adhesion to the surface of a Ti6Al4V substrate. It would be desirable to apply the principles of nanotechnology to synthesize a new antibacterial surface protective metallic alloy coating material.
Thus, metallic glassy alloy powders for antibacterial coating solving the aforementioned problems is desired.